Subject: Re: [PATCH v2] net: mana: Batch ringing RX queue doorbell on receiving packets
On Thu, 22 Jun 2023 09:22:36 -0700 longli@linuxonhyperv.com wrote:
It's inefficient to ring the doorbell page every time a WQE is posted to the received queue.
Move the code for ringing doorbell page to where after we have posted all WQEs to the receive queue during a callback from napi_poll().
Tests showed no regression in network latency benchmarks.
Cc: stable@vger.kernel.org Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)")
If this is supposed to be a fix, you need to clearly explain what the performance loss was, so that backporters can make an informed decision.
I'm sending v3 to include the details.
drivers/net/ethernet/microsoft/mana/gdma_main.c | 5 ++++- drivers/net/ethernet/microsoft/mana/mana_en.c | 10 ++++++++-- 2 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c b/drivers/net/ethernet/microsoft/mana/gdma_main.c index 8f3f78b68592..ef11d09a3655 100644 --- a/drivers/net/ethernet/microsoft/mana/gdma_main.c +++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c @@ -300,8 +300,11 @@ static void mana_gd_ring_doorbell(struct gdma_context *gc, u32 db_index,
void mana_gd_wq_ring_doorbell(struct gdma_context *gc, struct gdma_queue *queue) {
- /* BNIC Spec specifies that client should set 0 for rq.wqe_cnt
* This value is not used in sq*/type,
queue->id, queue->head * GDMA_WQE_BU_SIZE,1);
queue->id, queue->head * GDMA_WQE_BU_SIZE,0);
}
This change needs to be explained in the commit message, or should be a separate patch.
Will explain the change in the commit message.
Thanks, Long
-- pw-bot: cr